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Re: [Phys-l] More Stupidity in state exams



While this may be shorthand, it confuses the students and makes them think
you get energy by breaking any bonds. It is not being pedantic, it is being
careful so that students understand that energy is always required to
"break" bonds and that you get energy by forming other bonds. Ignoring the
part of the reaction where the bonds are formed is a big problem. You have
a system which contains energy and by rearranging it, breaking and forming
new bonds, you have net energy output.

The energy rich terminology is not understood by students to mean that the
energy is higher compared to other bonds. This is because the idea of
negative energy does not have meaning to them. One conception is that bonds
would have negative energy. Again there is a difficulty with negative,
positive and zero which pose huge conceptual problems to students.

Language does matter in that it telegraphs analogies to students and
sometimes inappropriate analogies. (The word telegraph is an anacronism,
but I have never hear of telephoning or texting ideas. Perhaps it is very
appropriate because telegraphy is a code, and it may be misinterpreted.)

Again, you have to study and understand what students come in with, and what
your words convey to them. Then you have to be aware of what they actually
learn. This is student centered instruction. Many think that student
centered means doing what students want or enjoy, but the real meaning is
shaping instruction around the students for maximum effectiveness. To do
this you have to be aware of student conceptions. In this regard I think
physics is many years ahead of bio, chem, and math. This opinion has been
confirmed by a friend in Chem Ed Research (CER?).

John M. Clement
Houston, TX


The terminology 'energy-rich phosphate bonds'is not helpful in this
regard, but perhaps 'easily-disrupted-by-energy phosphate bonds' does
not have quite the same ring? Of course, energy does tend to be given
out when these bonds break (in the context of the whole reaction
going on), and I think some biologists feel it is therefore being
pedantic to point out that like any bond energy is required to break
them. I've rather come to the view that whilst this is an alternative
conception acquired by students, for some of the biologists this is
more a different formalism reflecting their own disciplinary concerns
and priorities rather than an actual misunderstanding of the science
(just as some chemistry teachers seem to think that explaining
patterns in successive atomic ionisation energies in terms of the
sharing out of nuclear force is fine as it's a useful heuristic that
generally works).